Existing display panels mainly include liquid crystal displays (LCDs) and organic light emitting diode (OLED) displays, where OLED display panels possess many outstanding properties such as self-luminous, low driving voltage, high electroluminescent efficiency, short response time, high resolution and contrast, near 180 degree of view angle, wide range of working temperatures, amenability to flexible displays, large scale full-color display, etc. The OLEDs are considered to be display panels having greatest potential for development.
In the conventional art, as shown in FIG. 1, a conventional display panel comprises an array substrate disposed with a color filter substrate, the array substrate includes a first substrate layer 101, a first metal layer 102, a first insulating layer 103, a second metal layer 104, a protective layer 105 and a public electrode 106 arranged in sequence. The color filter substrate includes a second substrate layer 201, a black matrix 202, a color resist layer 203 and a public electrode layer 204 arranged in sequence. The substrate assay and the color filter substrate are secured by a frame and formed a sealed space. The sealed space is filled with a liquid crystal material and a photo spacer. The photo spacer includes a main photo spacer and a sub photo spacer. The main photo spacer and the second photo spacer positioned on one side of the color filer substrate, wherein the photo spacer (PS) and the black matrix (BM) are made of different materials and made using different manufacturing processes, wherein the photo spacer (PS) is a transparent material. Using a technique of photomask of gray tone mask (GTM) or half tone mask (HTM), produces a main photo spacer (Main PS) and a sub photo spacer (Sub PS) with different heights.
A black photo spacer (BPS) is a black flexible material. The black photo spacer not only shields light as a BM, but also supports the display area as a PS. Present BPS material makes the combination of the manufacturing processes of black matrix BM and PS possible. This technique saves one manufacturing process in manufacturing liquid crystal panels, and saves money, including costs produced by mask costs, manufacturing processes, instrument platforms, etc. Owing to the photomask technique of the multi-tone mask (MTM), the BPS is able to be exposed under three different exposure intensities, and achieved a BPS pattern with three different thicknesses of a BM, a Main PS, and a sub PS after patterning. The technique of MTM is sophisticated and expensive. Also, since achieving three heights, the manufacturing process of BPS is complicated.